‘approx’ is only valid for normality. if dist = ‘exp’,
table is returned.
‘approx’ uses the approximation formula of Dalal and Wilkinson,
valid for pvalues < 0.1. If the pvalue is larger than 0.1, then the
result of table is returned

For normality:
‘table’ uses the table from Dalal and Wilkinson, which is available
for pvalues between 0.001 and 0.2, and the formula of Lilliefors for
large n (n>900). Values in the table are linearly interpolated.
Values outside the range will be returned as bounds, 0.2 for large and
0.001 for small pvalues.
For exponential:
‘table’ uses the table from Lilliefors 1967, available for pvalues
between 0.01 and 0.2.
Values outside the range will be returned as bounds, 0.2 for large and
0.01 for small pvalues.